linux-kernel - Re: [PATCH] mm/memory-failure: teach kill_accessing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <eade3d62-8102-22a0-637e-ae2e34f11406@huawei.com>
Date: Fri, 19 Dec 2025 16:01:46 +0800
From: Miaohe Lin <linmiaohe@...wei.com>
To: Jane Chu <jane.chu@...cle.com>
CC: <muchun.song@...ux.dev>, <osalvador@...e.de>, <david@...nel.org>,
	<jiaqiyan@...gle.com>, <william.roche@...cle.com>, <rientjes@...gle.com>,
	<akpm@...ux-foundation.org>, <lorenzo.stoakes@...cle.com>,
	<Liam.Howlett@...cle.com>, <rppt@...nel.org>, <surenb@...gle.com>,
	<mhocko@...e.com>, <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mm/memory-failure: teach kill_accessing_process to accept
 hugetlb tail page pfn

On 2025/12/19 14:28, Jane Chu wrote:
> When a hugetlb folio is being poisoned again, try_memory_failure_hugetlb()
> passed head pfn to kill_accessing_process(), that is not right.
> The precise pfn of the poisoned page should be used in order to
> determine the precise vaddr as the SIGBUS payload.
> 
> This issue has already been taken care of in the normal path, that is,
> hwpoison_user_mappings(), see [1][2].  Further more, for [3] to work
> correctly in the hugetlb repoisoning case, it's essential to inform
> VM the precise poisoned page, not the head page.
> 
> [1] https://lkml.kernel.org/r/20231218135837.3310403-1-willy@infradead.org
> [2] https://lkml.kernel.org/r/20250224211445.2663312-1-jane.chu@oracle.com
> [3] https://lore.kernel.org/lkml/20251116013223.1557158-1-jiaqiyan@google.com/
> 

Thanks for your patch.

> Cc: <stable@...r.kernel.org>
> Signed-off-by: Jane Chu <jane.chu@...cle.com>
> ---
>  mm/memory-failure.c | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)
> 
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 3edebb0cda30..c9d87811b1ea 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -681,9 +681,11 @@ static void set_to_kill(struct to_kill *tk, unsigned long addr, short shift)
>  }
>  
>  static int check_hwpoisoned_entry(pte_t pte, unsigned long addr, short shift,
> -				unsigned long poisoned_pfn, struct to_kill *tk)
> +				unsigned long poisoned_pfn, struct to_kill *tk,
> +				int pte_nr)
>  {
>  	unsigned long pfn = 0;
> +	unsigned long hwpoison_vaddr;
>  
>  	if (pte_present(pte)) {
>  		pfn = pte_pfn(pte);
> @@ -694,10 +696,11 @@ static int check_hwpoisoned_entry(pte_t pte, unsigned long addr, short shift,
>  			pfn = swp_offset_pfn(swp);
>  	}
>  
> -	if (!pfn || pfn != poisoned_pfn)
> +	if (!pfn || (pfn > poisoned_pfn || (pfn + pte_nr - 1) < poisoned_pfn))
>  		return 0;

Can we get pte_nr from @shift? I.e. something like "pte_nr = 1UL << (shift - PAGE_SHIFT);"?

Thanks.
.